RESUMO
Intraoperative fluoroscopic parameters have shown to be poor predictors for ankle syndesmosis reduction, with up to 52% of syndesmotic malreduction (SMR) reported in the literature. Anteroposterior Tibio-Fibular index (APTF) was previously described to evaluate sagittal tibiofibular alignment in lateral ankle radiographs with a high correlation between both ankles in uninjured subjects. Reproducible intraoperative measurements for sagittal syndesmotic reduction are lacking. We propose the use of the "cAPTF," calculated as the absolute difference between the APTF of the non-injured and the operated ankle, to evaluate sagittal syndesmotic reduction. OBJECTIVE: Determine the predictive capability of cAPTF for SMR. METHOD: Prospective observational study. INCLUSION CRITERIA: patients with unstable ankle fractures requiring syndesmotic fixation, with a healthy contralateral ankle. Intraoperatively APTF was measured in both ankles after syndesmotic fixation. Postoperatively cAPTF was calculated. Only direct syndesmosis visualization through the lateral approach and AP and mortise views were used by surgeons to assess syndesmotic reduction. Quality of syndesmotic reduction was evaluated with bilateral postoperative CT. To estimate cAPTF discriminatory power for SMR, a receiver operative characteristic (ROC) curve was obtained and the area under the ROC curve was calculated. Youden index was used to determine the ideal cAPTF cut-off value for predicting SMR. For this determined cut-off value, sensitivity, specificity, and likelihood ratio were calculated. RESULTS: Fifty-two patients were included. Sixteen (30%) had SMR. Patients with SMR had a statistically significant higher cAPTF value than the well reduced (median 0.26 vs 0.09; P < 0.01). The cAPTF cut-off value to predict SMR was 0.161. A cAPTF greater than 0.161 had 100% sensitivity and 97,2% specificity for SMR. The area under the ROC curve was 0.99. CONCLUSION: Intraoperative cAPTF has excellent discriminatory power for predicting syndesmotic malreduction. We propose the routine use of intraoperative bilateral comparative fluoroscopy to assess sagittal syndesmotic reduction.
Assuntos
Fraturas do Tornozelo , Traumatismos do Tornozelo , Fraturas do Tornozelo/diagnóstico por imagem , Fraturas do Tornozelo/cirurgia , Traumatismos do Tornozelo/diagnóstico por imagem , Traumatismos do Tornozelo/cirurgia , Articulação do Tornozelo/diagnóstico por imagem , Articulação do Tornozelo/cirurgia , Fluoroscopia , Fixação Interna de Fraturas , Humanos , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND DATA: A new pilon fracture classification system based on CT scan data was recently published, showing almost perfect interobserver and intraobserver agreement among the authors who developed it. However, an independent assessment has not been done. OBJECTIVE: To do an independent agreement evaluation of the new pilon fracture classification system with physicians with different levels of expertise in the management of pilon fractures. METHODS: Seventy-one cases of acute pilon fracture were retrospectively collected. Fractures were classified by six evaluators (three foot and ankle surgeons and three orthopaedic surgery residents) using CT scans according to the morphological grading of the new pilon fracture classification system developed by Leonetti et al. Cases were presented to the same evaluators in a random sequence after a 6-week interval to determine intraobserver agreement. The kappa coefficient (κ) was used to determine agreement among evaluators. RESULTS: The interobserver agreement was substantial regarding the main fracture type (I, II, III, or IV), with an overall κ value of 0.69 (0.65 to 0.72). When including the II and III subtypes, the overall agreement was still substantial, with a κ value of 0.61 (95% confidence interval: 0.58 to 0.64). The intraobserver agreement was substantial when considering the main fracture categories (I, II, III, or IV), with a κ value of 0.78 (confidence interval: 0.72 to 0.84), and full agreement at the type level was observed in 76% (324/426) of evaluations. There was no notable difference between the foot and ankle surgeons and orthopaedic surgery residents in the interobserver and intraobserver agreement. CONCLUSION: The new classification system demonstrated substantial interobserver and intraobserver agreement between evaluators with different levels of expertise in the management of pilon fractures. Prospective studies should be done to evaluate its prognostic value and utility in clinical practice.